Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/10—Metal compounds
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
  • A01N59/16—Heavy metals; Compounds thereof
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
  • A01N59/16—Heavy metals; Compounds thereof
  • A01N59/20—Copper
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L29/00—Materials for catheters, medical tubing, cannulae, or endoscopes or for coating catheters
  • A61L29/14—Materials characterised by their function or physical properties, e.g. lubricating compositions
  • A61L29/16—Biologically active materials, e.g. therapeutic substances
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
  • C08J3/203—Solid polymers with solid and/or liquid additives
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2300/00—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
  • A61L2300/10—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices containing or releasing inorganic materials
  • A61L2300/102—Metals or metal compounds, e.g. salts such as bicarbonates, carbonates, oxides, zeolites, silicates
  • A61L2300/104—Silver, e.g. silver sulfadiazine
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2300/00—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
  • A61L2300/40—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices characterised by a specific therapeutic activity or mode of action
  • A61L2300/404—Biocides, antimicrobial agents, antiseptic agents
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2300/00—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
  • A61L2300/60—Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices characterised by a special physical form
  • A61L2300/606—Coatings

Definitions

• This invention relates to processes for producing plastic bodies that can be further processed, particularly for use in the medical field, and exhibit an antimicrobially effective content of metals or metal compounds (in the following called active agents).
• materials and/or compounds thereof whose oligodynamical effect is known, such as silver, copper and gold, but also other heavy metals such as zinc and also lanthanides that have an effect on bacteria and/or fungi as desired according to this invention, i.e. they eliminate them, they prevent them from multiplying as well as from sticking to or embedding themselves in the plastic, or at least largely keep them from doing so.
• Another way of avoiding the high material costs for antimicrobial finishing is not to subject the plastic as a whole to antimicrobial finishing but to coat the finished objects produced from this plastic with active agents.
• the problem underlying the present invention is thus to provide a method for producing oligodynamically active plastic bodies not exhibiting the aforementioned disadvantages, i.e. that are easy to produce, require only small amounts of oligodynamical metal and/or the compound(s) thereof and uniformly act on all surfaces, also on those that are hard to get to.
• a method for producing plastic bodies having a content of one or several oligodynamically active metal(s) or metal compounds as an active substance characterized in that the active substance is embedded in the plastic in the form of discrete particles, wherein the amount of active substance is no more than 1.0 wt. %, preferably no more than 0.5 wt. %, based on the total weight of the plastic body, and the maximum size of the discrete active substance particles is less than 500 nm.
• Active substances in powder form of any kind that are easy to handle are only produced and for sale with finenesses of grain up to the micron range (i.e. ⁇ 1 ⁇ m) and sub-micron range (i.e. >0.1 ⁇ m).
• the thus achieved specific surface for instance in the case of the finest commercially available silver powder having a rated grain size of 2-3.5 ⁇ m, which of course comprises also a certain portion of coarser particles and sub-micron particles, which is unavoidable, amounts to 0.5 to 1 m 2 /g.
• Other frequently used and also less expensive silver powders have even larger particles and correspondingly lower specific surfaces.
• colloidal preparations can generally only be prepared as sols or gels.
• the thus present portion of protective colloid during further processing and use usually involves considerable undesired side effects.
• colloidal preparations are often rather unstable and, in addition, often relatively expensive.
• plastic bodies are therefore preferably produced such that the blank is coated with the bactericidally and/or fungicidally (oligodynamically) active substance by means of a chemical or physical process, the obtained blank (pre-product) is comminuted and/or molten down, from which mass the desired plastic body is then produced according to common methods.
• Very thin and, depending on the process, fine and even extraordinarily fine structures of the deposited material can be achieved by means of physical and chemical methods for coating surfaces, which structures correspond to or at least come close to the fineness of colloidal preparations. This holds true especially when the deposited layers are very thin.
• the resulting minimum value of the specific surface is 19 m 2 /g for such coatings, for instance just by mathematic calculation of the outer geometry at a layer thickness of 10 nm e.g. for the deposition of silver.
• the layer thickness is 1 to 50 nm.
• the maximum particle size distribution of the active substance is below 100 nm in at least one dimension (e.g. in particles present in the form of flocks or flakes), more preferably 10 nm.
• the grain size may even be smaller than 1 nm.
• Crystalline materials (PTFE, some polyimides) must e.g. be comminuted by grinding; remelting is not possible (in practice). They are then shaped as desired by e.g. (pressure) sintering.
• Plastics having principally a low but most finely dispersed content of metal particles (or particles of metal compounds) with a correspondingly large specific active surface have the same effect as plastics having a considerably higher but less finely dispersed content of metals (or metal compounds) with a correspondingly smaller specific active surface.
• plastics produced according to the above-mentioned method that for particularly critical cases these plastics may be equipped with metal (or metal compounds) having particles whose size may be influenced for an optimum long-term effect from the very beginning by a suitable process for the production of the layer.
• the coating can take place on film (see Example), which can then be re-comminuted and further processed. It may also be applied to fibers or granules with the same end result of the production of the desired final concentration of the active substance in the plastic.
• Plastic blanks that already contain fillers may also be used. Preferred are plastic blanks whose fillers do not considerably alter the chemical and physiological properties of the plastic used as a pre-product. Preferred fillers are those that result in the end products produced therefrom being easily recognizable by means of X-rays and/or having an increased specific weight (e.g. aprons); barium sulfate is frequently used for this purpose in the state of the art. In addition, plastic blanks containing fillers have a larger surface, a fact that is advantageous in the coating of this invention (better dispersion).
• plastics in the form of films, ribbons (a special kind of film), fibers or granules with one or more active substances in thin layers, preferably with layer thicknesses of between 10 and 100 nm, is possible in various ways using chemical and, above all, physical methods.
• thermoplastic polyurethane is a preferred plastic raw material. Mention be also made of novel plastics that are similar to common polyurethanes (e.g. "carbothanes").
• the purpose of the process variants listed in the following is to bring the plastic containing active substance after the coating process into a form that makes it possible to further process it in mixers, kneaders, extruders or other machines to form intermediates and/or to make final processing possible in extruders, injection molding machines or in other equipment, such as (hot-) pressing.
• the plastic is taken out of the coating equipment, transported, stored and transported to the extruder (packaging under exclusion of air or even under protective gas)
• the plastic that has (or might have) accepted moisture is once again effectively dried before the extrusion step, preferably right at the extruder.
• uncoated film or fibers also uncoated granules
• drying fibers a second time is a little more difficult and drying film a second time directly at the extruder requires special equipment that is unlikely to be available.
• the surface of the active substance per volume unit plastic that is effective after further processing depends only on the obtained number of layers of active substance per thickness unit plastic after the coating step, i.e. it depends only on the thickness of the film and on whether the film is coated single- or double-sided.
• the thickness of the coating merely determines the supply of active substance, i.e. the time span how long the system remains effective.
• the chosen coating method and the parameters used therein especially also the parameters used in the coating process for the pretreatment of the surface (e.g. in glimming or sputter etching), have considerable influence on whether a prepared layer is only seemingly (optically) or really impermeable to water vapor.
• Uncoated interfacial film may be used to prevent direct contact of the coated surfaces. These uncoated interfacial films must, of course, be taken into account in the balance "coating layers per thickness unit plastic".
• interfacial film renders the issue of moisture absorbance important for the following process steps, which issue had been almost eliminated by the double-sided coating of the (hygroscopic) plastic film.
• mass required for such interfacial films relative to the mass of the coated film is smaller by at least a factor of two.
• the interfacial films too must be dried in some way before they are used, together with the coated plastic film, in a process involving temperatures that are relatively high (for plastics).
• the chopped product would be rather suitable for being fed into processing machines with appropriate feeding equipment, e.g. "packing screws".
• Films can be economically produced in large quantities in any desired width and, above all, in almost any desired strength. The latter possibility leads to a very wide variety of possible content of active substance surface per volume unit, which after all determines the effectiveness of the finished plastic.
• the use of film as a raw material is always to be considered when average-sized active substance surfaces per volume unit plastic are to be produced. The problems of further processing the plastics are acceptable when the produced amount is high enough.
• Granules can be economically produced in large quantities; however, only in a rather restricted diameter range.
• the ratio of surface to volume is defined strictly (linear) dependent on the diameter of the granules. This property results in a very reduced possibility of variations for the content of active substance surface per volume unit, which after all determines the effectiveness of the finished plastic.
• Fibers can be produced somewhat economically in large quantities.
• Ribbons are a special kind of film. They can be produced economically in large quantities in any desired width and strength. The latter option leads to a very wide variety for the possible content of active substance surface per volume unit plastic, which after all determines the effectiveness of the finished plastic.
• the use of ribbons as a raw material is always to be considered when average-sized active substance surfaces per volume unit plastic are to be produced. Ribbons can also be sufficiently coated on the narrow sides so that they can then be considered coated all around.
• ribbons can easily be fed into many extrusion machines without further pre-communition (and the usually following further intermediate steps), which leads to a decisive simplification of the entire manufacturing process of plastics of this invention but of course involves the use of higher amounts of active substance.
• Double-sided coating of the film with only one active substance makes it possible to eliminate any re-drying steps before further processing and/or final processing when the coating is water-vapor impermeable all around, but it involves a loss of active substance surface in the end product in the course of the further and/or final processing because it cannot be avoided that active substance surfaces are pressed onto one another during further processing.
• Another embodiment is characterized in that at first a coated plastic blank is produced according to one of the above-described methods but with a higher concentration of one or more antimicrobially active metal(s) and/or metal compound(s); this coated plastic blank is subsequently comminuted or molten down together with uncoated plastic blanks and is finally given the desired shape according to common methods.
• the uncoated plastic blanks may be made of the same and/or other plastic(s) as the coated plastic blank.
• Approx. 80 cm 2 -large polyurethane films of 0.25 mm thickness were vapor-deposited with a silver layer of approx. 10 nm thickness in a high-vacuum system for antireflection coating of optical lenses. Under a light microscope the silver layer showed no inherent structure whatsoever, only the unevenness of the film could be seen as unevenness of the coating. Subsequently, the films were comminuted and molten down under stirring at approx. 240° C. Specimen (little platelets) were produced from this mass by means of hot-pressing.
• the used plastic samples were produced by hand by means of melting and stirring under controlled thermal conditions.
• each of the samples in the form of sheets having a diameter of 132 mm received 8 cup-shaped indentations having a volume of 0.5 ml each.
• test sheets were produced from permanently thermoplastic polyurethane films "Platilon U 073", (polyether type) 0.18 mm thick that were coated with
• test sheets a) and c) were produced twice.
• Staphylococcus epidermidis 5 ⁇ 10 7 germs/ml
• Staphylococcus aureus 5 ⁇ 10 7 germs/ml
• Streptococcus faecalis 5 ⁇ 10 7 germs/ml
• Escherichia coli 5 ⁇ 10 7 germs/ml
• Pseudomonas aeruginosa 5 ⁇ 10 7 germs/ml
• Candida albicans 5 ⁇ 10 7 germs/ml
• the sheets were positioned in an incubator and kept there for 48 hours.
• the content of the cups is, judging by visual appearance, dried up.
• the sheets were removed from the incubator and the cups were refilled with physiological salt solution. After another 15 minutes the newly formed suspension was removed and introduced into nutrient broth.
• plastic here mainly regarding its capability to accept water and make diffusion of metal ions possible, above all
• the ratio of active surface per volume unit plastic determine the effectiveness rather than the weight percentage of active substance in the plastic, particularly since in all examined cases this portion is by far less than what it should at least be for demonstrable effectiveness according to available patent publications.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Medicinal Chemistry (AREA)
• Engineering & Computer Science (AREA)
• General Health & Medical Sciences (AREA)
• Organic Chemistry (AREA)
• Pest Control & Pesticides (AREA)
• Inorganic Chemistry (AREA)
• Plant Pathology (AREA)
• Wood Science & Technology (AREA)
• Zoology (AREA)
• Environmental Sciences (AREA)
• Polymers & Plastics (AREA)
• Agronomy & Crop Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Dentistry (AREA)
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• Veterinary Medicine (AREA)
• Public Health (AREA)
• Biomedical Technology (AREA)
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• Animal Behavior & Ethology (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Laminated Bodies (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Materials For Medical Uses (AREA)
• Acyclic And Carbocyclic Compounds In Medicinal Compositions (AREA)
• Medicinal Preparation (AREA)

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• 1995
  • 1995-02-01 AT AT95906894T patent/ATE155649T1/de active
  • 1995-02-01 WO PCT/DE1995/000122 patent/WO1995020878A1/fr active IP Right Grant
  • 1995-02-01 DE DE59500419T patent/DE59500419D1/de not_active Expired - Lifetime
  • 1995-02-01 US US08/663,161 patent/US5976562A/en not_active Expired - Lifetime
  • 1995-02-01 EP EP95906894A patent/EP0711113B1/fr not_active Expired - Lifetime
  • 1995-02-01 DK DK95906894.1T patent/DK0711113T3/da active
  • 1995-02-01 ES ES95906894T patent/ES2107913T3/es not_active Expired - Lifetime
  • 1995-02-01 CA CA002182390A patent/CA2182390C/fr not_active Expired - Lifetime
• 1999
  • 1999-11-01 US US09/431,199 patent/US6544536B1/en not_active Expired - Lifetime

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